The brain still develops into adulthood
Brain development does not stop in adulthood. To believe the work published in Science , the brain region involved in face recognition continues to grow throughout life. A surprising discovery that challenges certain dogmas of neuroscience.
Experts estimate that after a strong period of production of neurons between 0 and 3 years, a phenomenon of pruning takes place to keep only the necessary cells. These billions of neuronal connections then calmly mature until about 25 years, before stabilizing the genesis and destruction of the synapses.
But it would seem that this cerebral development is still much more complex than was thought.
Researchers at Stanford University (USA) made this discovery by chance by trying to better understand facial recognition, a crucial ability in social interactions. They studied for this purpose the images taken by MRI of 22 children of 5 to 12 years and 25 adults of 22 to 28 years invited to pass several tests to compare their capacity to recognize faces and places.
Surprisingly, initial observations suggest that the region responsible for face recognition is larger in adults than children, whereas the recognition of places is identical between the two groups.
A result confirmed by the study of brains of deceased adults. “We clearly saw this tissue proliferate,” says Jesse Gomez, lead author. Many people assume a pessimistic view of brain development. They assume that tissue degenerates slowly as they age. Now, we have found the opposite: that whatever neurons remain of childhood, they continue to develop “.
The researchers point out that this cerebral region does not accommodate new neurons. It is those already present that create new connections between them. Glial cells, cells present to support neurons, are also recruited to feed these ultra-connected neurons.
These results may have repercussions in terms of health, explain the authors. They specify that 2% of adults have difficulty recognizing faces. They suffer from prosopagnosis. For these people, daily life is hell. In the most severe forms, they are unable to recognize their loved ones if they cross them at the supermarket.
“If you told me five or ten years ago that we would be able to measure the growth of this tissue in vivo, I would not have believed it,” enthuses Kalanit Grill-Spector, one of the authors of The study. This shows that there are real changes in the brain that occur throughout development. It’s fantastic “.